Q.11 A particle of mass 3 kg moves under the force of
4i+8j+10k N. If the particle starts from rest
and was at origin initially. Its new co-ordinates
after 3 second is-
(1) (4, 8, 10) (2) (6, 12, 15)
(3) (2, 4,5) (4) (3, 6, 7.5)
Answers
Kinematics in 3-dimensions
To solve the problem, we can consider the motion independently along all the three dimensions.
Mass m = 3 kg
Force
Time t = 3 s
Initial Velocity u = 0 m/s
Consider the motion individually along the x, y and z directions.
The X-Direction
Here,
So, the acceleration would be
Hence, the displacement along x-direction can be calculated as:
[Note that we have already got the Answer. Option 2: (6, 12, 15). We will still solve the question for the sake of completion.]
The Y-Direction
Here,
So, the acceleration would be
Hence, the displacement along y-direction can be calculated as:
The Z-Direction
Here,
So, the acceleration would be
Hence, the displacement along z-direction can be calculated as:
Thus, we have our new co-ordinates:
x = 6 m
y = 12 m
z = 15 m
Hence, The Answer is Option 2: (6, 12, 15)
Hey there
refer to attachment